Jack for knitting machines



March 9, 1937. R. H. LAWSON ET AL JACK FOR KNITTING MACHINES Filed Jan. 13, 1956 f/vyzwmfiw zPaaaEm Ef ZAWS'WY MALAY/v4. Snxm; Me y 7? xmwlf,

- ,ATTTy.

Patented Mar. 9 1937 UNlTED sir JAGK roe. KNETTING MACHINES Massachusetts Application January 13, 1936, Serial No. 58,853

s Claims-Q kol. 66-407) This case concerns knitting machines of a type wherein sinkers are movable in opposition to the movement of needles for the purpose of measuring and drawing loops. The machine herein illustrated has jacks which are employed for movingthese sinkers and these jacks have been improved over those formerly employed as illustrated in United States application Ser. No. 7,248, filed February 19, 1935.

In the drawing: 1

Fig. 1 is a sectional view showing a needle, a cooperating sinker and the jack for moving'said sinker, all parts being shown greatly enlarged;

Fig. 2 is a sectional View showing a few needles, sinkers and sinker jacksas well as cams for operating sinker jacks;

Fig. 3 is a section taken through the sinkers and needles just above the top of sinker jacks; and

Fig. 4 is a detail greatly enlarged and showing the nibs of a sinker jack engaging a sinker.

The machine to which this invention refers includes a plurality of individually movable needles I, a like number of sinkers 2 and sinker jacks 3 slideable within the needle slots but independently of the needles for raising and lowering sinkers as in the case above identified. It is a special feature of such a machine that sinkers move upwardly while needles move in the opposite direction, both cooperating in drawing each loop and thus a vertical movement of sinkers must be provided in addition to the well-known radial movements. Each sinker 2 has a butt 4 Which in cooperation with sinker cams imparts these radial movements, and each jack 3 has a pair of nibs 5 and 6 which engage on either side of a projection 1 extending as an integral part of each sinker. The sinker rocks about its rearmost portion as indicated at 8 and is guided within slots in a sinker ring 9 and other slots in a stitch ring (notshown). The full line position of Fig. 1 illustrates a'sinker and sinker jack in uppermost or stitch drawing position while the dot and dash line shows the oppposite or lowermost position. It can be seen that nibs 5 and 6 have a movement relative to extension 1 due to the .rocking of the sinker and also due to the movement of the sinker radially. It is the purpose of this invention to so position nibs v5 and 6 that a minimum of wear will occur between the nibs and extension, that a very small clearance may be allowed between these elements and that no binding of the same will be experienced, and that radial movements of sinkers will not tend to force jacks and needles out of their slots.

Nibs 5 and 5 have been oiTset as illustrated in Figs. 1; 3 and 4 and the timing or positioning of parts has been so arranged that the sinker. never moves above a position wherein extension? passes the horizontal, in other words, the movement of element 1 is between the horizontal and angles. below the horizontal. In constructing the nibs on jack 3 the vertical distance between them is madev as near to the vertical height of extension E as is possible with provision for a working fit. This assures that in upper position nibs 5 and 6 will positively limit movement of the sinker and will also assure that each sinker does rise to a definite limit. This is important since the uppermost position to which sinkers rise is one factor determining the length of stitch. There will be no binding of the nibs 5 and 6 on extension 1 in either position and it has not been found necessary to undercut this extension as was necessary on the sinker previously employed. In lowermost position as illustrated in Fig. 4, the nibs being offset as they are, additional clearance is automatically provided. After being raised by cam I0, Fig. 2, each jack butt ll follows along the extended guiding surfaces and is slightly depressed by cam l2 to relieve the stitch. Radial movements of the sinker and necessarily element 1 will be accomplished while the jack is in a lowered or slightly lowered position so that nibs 5 and 6 will have attained somewhat the position shown in Fig. 4 relative to the extension 1 and thus, this radial movement will produce a minimum of friction and wear at the point of contact. In the form of the invention illustrated we have shown the sinker rising to the horizontal, but in actual practice it has been found better to time these elments so that they reach their uppermost point of travel just short of the horizontal so that there is never any danger of their passing the horizontal, a condition to be avoided.

With the construction previously employed the nibs on the jack engaged the extension on the sinker more closely as the-sinker was pulled outwardly of the machine, a construction tending to pull jacks outwardly of their slots and consequently to allow needles behind the jacks to get out of alignment. It is a feature of this new jack that the tightest condition prevails while the sinker is being pushed inwardly, at a time when jacks and needles can not be displaced even though there were a slight binding between some sinkers and their jacks. As the. sinkers of this case are pulled outwardly an excess of clearance is always available so that no tendency to displace either jacks or needles is evident.

The invention has been described with respect to one specific embodiment of the same but it is to be understood that modifications and changes will occur to those skilled in the art which would still fall within the scope of the appended claims.

We claim:

1. In a knitting machine, the combination of needles and sinkers movable in opposite directions for measuring and drawing stitches, sinkcg jacks individual to each sinker for imparting movement thereto, each jack having a pair of superposed nibs for engagement with a part of the sinker, said nibs being offset so that in uppermost position they engage said sinker with a minimum of clearance and in all other positions provide an excess of clearance.

2. In a knitting machine, the combination of needles and sinkers, said sinkers being movable in opposition to the movement of needles for measuring and drawing stitches, an extension on each sinker and a jack having nibs thereon for engagement with said extension, said nibs and extension being so disposed that in stitch drawing position a minimum of clearance is provided between the same and in all other positions, said nibs provide a greater amount of clearance than in the stitch drawing position.

3. In a knitting machine of the type described, a sinker slidable radially and also free to pivot about a point adjacent its cam engaging end, an extension on said sinker and a jack having a butt thereon and a pair of nibs for engaging said extension on the sinker, the nibs bearing one above and one beneath the said extension, the upper nib engaging the extension farther from the point about which the sinker pivots than does the lower nib.

4. In a knitting machine of the type described, a sinker slidable radially and also free to pivot about a point remote from the stitch engaging end of the same, an extension on said sinker and a jack having nibs for engaging said extension said nibs being offset in a vertical plane so that a minimum of clearance is provided between nibs and extension in stitch drawing position but in lower position, an excess of clearance will be provided.

5. A jack for raising and lowering sinkers including a shank portion, a butt at one end and two nibs at the sinker engaging end, said nibs being disposed one above the other and offset in a vertical plane.

6. A jack for raising and lowering sinkers in a knitting machine including a shank portion, a butt at one end and a pair of nibs at the sinker engaging end, said nibs being disposed one above the other and the upper nib being offset in a vertical plane so that it engages the sinker farther from a point about which the sinker pivots than does the lower nib.

ROBERT H. LAWSON. WILLIAM L. SMITH, JR. 

